Lionel Cranfield Sackville was Constable of Dover Castle and Lord Warden of the Cinque Ports (1727-1765). He succeeded his father as 7th Earl of Dorset and 2nd Earl of Middlesex on 29 January 1706 and took his seat in the House of Lords on 19 January 1708. His portrait in Garter robes was painted by Kneller in 1719 (Government Art Collection, inv. no. 0/587) and the following year he was created Duke of Dorset. Dorset was Lord Lieutenant of Ireland from June 1730 until March 1737 and from 1750 until 1755. He probably commissioned P14A View of Dover as Constable of Dover Castle. A print by Johann Sebastian Müller (also known as Miller) was made in 1747 after this version of the painting, in Dorset's collection.